Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/24—Dialysis ; Membrane extraction
  • B01D61/243—Dialysis
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C227/00—Preparation of compounds containing amino and carboxyl groups bound to the same carbon skeleton
  • C07C227/14—Preparation of compounds containing amino and carboxyl groups bound to the same carbon skeleton from compounds containing already amino and carboxyl groups or derivatives thereof
  • C07C227/18—Preparation of compounds containing amino and carboxyl groups bound to the same carbon skeleton from compounds containing already amino and carboxyl groups or derivatives thereof by reactions involving amino or carboxyl groups, e.g. hydrolysis of esters or amides, by formation of halides, salts or esters
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/41—Preparation of salts of carboxylic acids
  • C07C51/412—Preparation of salts of carboxylic acids by conversion of the acids, their salts, esters or anhydrides with the same carboxylic acid part
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
  • C12P7/00—Preparation of oxygen-containing organic compounds
  • C12P7/40—Preparation of oxygen-containing organic compounds containing a carboxyl group including Peroxycarboxylic acids

Definitions

• the present invention relates to a process for the production of water-soluble salts.
• the present invention relates to a process for the production and utilization of water-soluble salts of carboxylic and amino acids.
• both carboxylic acids and amino acids formed on fermentation of carbohydrates are obtained in a fermentation broth containing residual carbohydrates and other impurities. Similar to mineral acids, they are usually purified prior to the neutralization which produces their salts, e.g., trisodium citrate is currently produced from pure citric acid recovered from fermentation broth by a sequence of separation methods, and monosodium glutamate is currently produced from pure glutamic acid recovered from fermentation broth by a sequence of separation methods.
• Micrococcus qlutamicus (afterwards renamed as
• Corynebacteriu qluatamicum which accumulates about 30% L-glutamic acid based on the original glucose in its cultivating broth. This discovery led to microbial production of several amino acids by inducing artificial mutants. As is now known, glutamic acid-producing microorganisms are well-distributed throughout the natural environment. They are classified taxonomically as the Micrococcus, Brevibacterium, Corynebacteriu , Arthrobacter and
• Microbacterium genera They all have intense glutamate dehydrogenase activity and oxidative degradability, to both L-glutamic acid and ⁇ -ketoglutaric acid.
• the carbon sources for biosynthesis of glutamic acid include acetic acid and the commonly used carbohydrates.
• microorganisms used for glutamic acid fermentation are usually preserved under lyophilization or, for shorter periods, by keeping the stock culture below 10-15°C.
• the refreshed microorganisms are then cultivated in a liquid medium in a flask and are shaken vigorously; they are then transferred into a small fermentor to let them propagate to about 10 kL for seed culture.
• Industrial-scale fermenters are pressure-tight, stainless steel containers, built to hold up to several hundred kiloliters of cultivating medium. They are equipped with aeration and stirring devices, as well as other automatic controls. Fermentation takes from 35 to 45 hours.
• the fermented broth After sterilization either in the fermenter or by a heat exchanger, the fermented broth is transferred to another vessel; then it is centrifuged to remove microorganism cells and other solid organic matter.
• the pH is adjusted to 3.2, using hydrochloric acid. This precipitates crude L-glutamic acid crystals, the raw material for purified monosodium L-glutamate.
• U.S. Patent No. 3,944,606 suggests the formation of sodium citrate by a combination of extraction and neutralization steps.
• the acid is extracted from an aqueous feed containing the same into an extractant which, after phase separation, is contacted with NaOH solution.
• Sodium citrate is formed and the extractant is regenerated.
• a similar method is known for the production of calcium acetate, a de-icer.
• Acetic acid is extracted from fermentation broth. The extract is then contacted with lime milk to form the acetate, and the extractant is then recovered for reuse.
• Solvent extraction utilizing organic solvents which require mixing of the phases and their separation, may not be attractive in many cases, particularly in such cases in which the extractant contaminates the product.
• the extraction/neutralization process can serve not only as a purification means, but also for concentration of the product.
• the water content of the product solution may be limited to the water introduced with the base.
• Such a combination of purification and concentration is attractive, particularly in cases in which the feed acid solution is dilute.
• achievement of purification and concentration through extraction and neutralization has an inherent disadvantage in that extraction from dilute solutions requires large volumes of the extractant, resulting in large volumes in both the extraction and neutralization stages.
• Purification and concentration are particularly advantageous if continuous removal of the product acid from the fermentation liquor is achieved, thus providing continuous fermentation.
• the drawbacks of extraction are obvious: the operation is complicated and large volumes are required.
• the extractant in many cases, has a toxic effect on micro-organisms.
• water-soluble salts selected from the group consisting of water-soluble salts of carboxylic acids and water-soluble salts of amino acids, comprising reacting an aqueous feed solution containing an amino or carboxylic acid or their anions with a water-soluble base, in indirect contact via a semi-permeable membrane, said membrane being permselective to amino acids, carboxylic acids and their anions over cations and non-ionized species, whereby there is formed a salt solution of said acid, containing less impurities per anion than said feed solution and utilizing said salt values from said formed salt solution of said acid.
• a process for the production and utilization of water-soluble salts of amino acids comprising reacting an aqueous feed solution containing an amino acid or its anion with a water-soluble base in indirect contact, via a semi-permeable membrane, said membrane being permselective to amino acids and their anions over cations and non-ionized species, whereby there is formed a salt solution of said amino acid, containing less impurities per anion than said feed solution and utilizing said salt values from said formed salt solution of said amino acid.
• said amino acid is selected from the group consisting of glutamic acid, lysine and aspartic acid.
• a process for the production and utilization of water-soluble salts of carboxylic acids comprising reacting an aqueous feed solution containing a carboxylic acid or its anion with a water-soluble base in indirect contact, via a semi-permeable membrane, said membrane being permselective to carboxylic acids and their anions over cations and non-ionized species, whereby there is formed a salt solution of said carboxylic acid, containing less impurities per anion than said feed solution and utilizing said salt values from said formed salt solution of said carboxylic acid.
• said carboxylic acid is selected from the group consisting of citric, lactic and acetic acids.
• the water-soluble bases preferably used in the present invention are selected from alkali, alkaline earth, or ammonium hydroxide or carbonate.
• An advantage of the preferred embodiments of the present invention is that the concentration of carboxylic acid anions in said formed salt solution is higher than the concentration of said carboxylic acid anions in said aqueous feed solution.
• said salt is crystallized and recovered from said salt solution.
• direct contact between an acid and a base is performed by mixing an acid or its aqueous solution with a base or its aqueous solution, while indirect contact between an acid and a base is a reaction between acid (or its solution) and a base (or its solution), separated by a semi-permeable membrane.
• Semi-permeable ion-exchange membranes are known and commercially available. Their main use is in the field of water desalination by processes in which ions are caused to migrate across such membranes from a dilute to a concentrated aqueous solution under the influence of an electric field and, to a lesser degree, in a so-called “Donnan dialysis” in which ions are exchanged between two aqueous solutions across an ion-exchange membrane.
• the product acid is withdrawn continuously from a fermentation broth by indirect contact neutralization with a water-soluble base during the course of fermentation.
• Said fermentation is normally carried out at a pH of at least 3 or higher, and should be maintained at such a pH at which the micro-organisms best function. This mode of operation also affords the additional advantage of preventing product inhibition without at the same time causing any pollution of the fermentation broth.
• At least one module consisting of two spaced membranes is fitted within the fermentor vessel and a solution of a base is continuously circulated between the membranes.
• fermentation broth is circulated continuously through a suitably-designed membrane module located outside the fermentor vessel and comprising at least one fermentation broth flow path and one base flow path.
• the fermentation broth withdrawn from the fermentation vessel may be filtered before its introduction into the membrane module for the removal of bio ass comprising microorganism cells and cell debris, in which case a hollow fiber membrane module may, for example, be used for the indirect contact neutralization. If the whole broth is circulated through the membrane module without preliminary removal of the biomass, a membrane module with wide enough channels between the membranes is necessary, e.g., such as is used in microfiltration processes for the separation of cells from fermentation media.
• the ion exchange membranes used for the purpose of the present invention should preferably be in the form of a leak-free convenient module, such as a potted capillary or a hollow fiber membrane tube-and-shell module, a spiralwound membrane sleeve, or any similar arrangement by which the two circulating streams are totally separate.
• the surface area per volume of an ion exchange membrane in a module is of the order of several m 2 per liter.
• the present invention utilizes at least one device, comprising at least two chambers separated by a semi-permeable membrane.
• the first chamber (hereinafter, “feed chamber”) of the device contains an impure aqueous solution of the carboxylic acid to be reacted (“feed solution”), while the second chamber contains the base.
• feed solution an impure aqueous solution of the carboxylic acid to be reacted
• second chamber contains the base.
• the product accumulates in the second chamber (referred to hereinafter as the "product chamber", since the desired salt is formed therein).
• the feed solution may be a fermentation liquor, or may contain such liquor.
• the acid is formed in the feed chamber due to chemical reaction or due to fermentation.
• a neutral solution will be considered a feed solution, since without pH control and base addition, the pH in the solution decreases with time, due to the formation of acid therewithin.
• U.S. Patent No. 4,775,478 (Voss and Bruecken) describes acid removal from a solution also containing water, solvent, low molecular weight substances and ions.
• Said patent refers to a particular case of cathodic electrocoating baths, in which electrically-conductive substrates are coated with cationic resins present in the form of aqueous dispersions. Part or all of the dip-coating bath is subjected to an ultrafiltration in which the ultrafiltration membrane retains the cationic resins and an ultrafiltrate is formed. This ultrafiltrate, or part of it, and an aqueous solution of an organic or inorganic base are each introduced into one or more chambers separated from each other by an anion exchange membrane.
• said invention while involved with withdrawal of an acid from a feed solution by indirect contact across an anion-exchange membrane, is directed and limited to an extraction method utilizing a water-immiscible organic extractant and thus is substantially different in concept and reactants from the process of the present invention.
• extraction methods utilize as an extraction agent a compound capable of forming an association product with a solute, and thereby are able to extract such a solute from an aqueous feed into a receiver solution wherein the loaded extractant is made to undergo dissociation to liberate the extraction reagent and thereby renders the extractant solution available for further extraction.
• both the desired acid salt and water are formed, and, in fact, in the present invention the cation of the reacting base forms a part of the desired final product.
• said prior extraction method is also different in concept and in reactants from the process of the present invention, and said prior specification certainly does not teach the use of a water-soluble base such as an alkali, alkaline earth or ammonium hydroxide or carbonate to form an amine salt or a carboxylic acid salt thereof.
• a water-soluble base such as an alkali, alkaline earth or ammonium hydroxide or carbonate to form an amine salt or a carboxylic acid salt thereof.
• membranes suitable for application in the process of the present invention are permeable to anions, but block the permeation of non-electrolytes and cations. Some of these membranes block protons with the cations, but that is not a requirement of the process. Suitable membranes comprise those described in U.S. Patent 4,775,478, the teachings of which are incorporated herein by reference.
• hydrophilic membrane provides for water transport between the chambers, driven by osmotic pressure.
• water may transfer to this chamber.
• pressure is applied in the product chamber by known means (e.g., those used in reverse osmosis) .
• the base fed into the product chamber is converted into the salt product.
• salt concentration in the product chamber increases with time.
• a salt-containing solution with some base added, may be introduced into the product chamber. Part of the solution obtained from the product chamber is recycled, while another part is further processed for salt recovery, or for other purposes.
• Product salt recovery is usually performed through cooling the solution obtained, or through evaporation/crystallization of said solution.
• C0 2 under pressure may be applied in the feed chamber. Precipitation of the carbonate or bi-carbonates enhances the production of the water-soluble salt.
• Solids and biomass present in the feed may be removed prior to introduction into the feed chamber, e.g., by ultrafiltration, to avoid fouling of the membrane.
• Water-immiscible bases, introduced into the product compartment, are, however, less problematic, as they are converted into water-soluble salts during the indirect reaction. These bases can be fed into the product chamber as a suspension in water.
• the process of the present invention is very useful in the production of calcium and magnesium acetate, used as de-icers. Dilute (about 3%) and contaminated acetic acid solution are obtained on fermentation of carbohydrates or cellulosic material. This solution is fed to the feed chamber, while a suspension of lime, limestone or dolomitic lime is fed into the product chamber.
• Acetic acid transfers through the membranes that block the impurities, and react with the base to form the corresponding acetate.
• High concentrations of the product salt are obtainable and high efficiency can be achieved in acetic acid conversion to the salt.
• the process is not dependent on complete conversion, as the solution obtained from the feed chamber can also be recycled to fermentation for re-enrichment.
• the recycled stream is free of solvent and other additives that may be toxic to the micro-organisms.
• a highly attractive embodiment of the present invention is the continuous separation of a formed amino acid from the fermentation broth during fermentation, and converting it to the required soluble salt.
• the present invention provides efficient conversion of amino acid, even from dilute fermentation broth, combined with purification and concentration. Such continuous conversion to purified, concentrated water-soluble salts is of particular interest in cases where efficient fermentation is limited to high pH values.
• the base instead of being added to the fermentation liquor in direct contact neutralization, is utilized in indirect contact via a semi- permeable membrane which separates the fermentation liquor from the base.
• a process for the production and utilization of water-soluble salts of amino acids, while concurrently facilitating a continuous fermentation of carbohydrates comprising reacting a fermentation liquor containing an amino acid or its anion as a fermentation product in a first reaction chamber, with a base in a second reaction chamber, in indirect contact via a semi-permeable membrane separating said chambers, said membrane being permselective to amino acids and their anions over cations and non-ionized species, whereby there is formed a salt solution of said amino acid in said second reaction chamber containing less impurities per anion than said fermentation liquor and utilizing said salt values from said formed salt solution of said amino acid, while concurrently adding additional base to said second reaction chamber to utilize the driving force of neutralization between said acid and said base, thereby drawing additional acid from said first chamber as it forms and thereby maintaining the pH in said first chamber at a level conducive to continuous fermentation.
• a further highly attractive embodiment of the present invention is the continuous separation of a formed carboxylic acid from the fermentation broth during fermentation, and converting, it to the required soluble salt.
• the present invention provides efficient conversion of carboxylic acid, even from dilute fermentation broth, combined with purification and concentration. Such continuous conversion to purified, concentrated water-soluble salts is of particular interest in cases where efficient fermentation is limited to high pH values.
• a process for the production and utilization of water-soluble salts of carboxylic acids, while concurrently facilitating a continuous fermentation of carbohydrates comprising reacting a fermentation liquor containing a carboxylic acid or its anion as a fermentation product in a first reaction chamber, with a base in a second reaction chamber, in indirect contact via a semi-permeable membrane separating said chambers, said membrane being permselective to acids and their anions over cations and non-ionized species, whereby there is formed a salt solution of said carboxylic acid in said second reaction chamber containing less impurities per anion than said fermentation liquor and utilizing said salt values from said formed salt solution of said carboxylic acid, while concurrently adding additional base to said second reaction chamber to utilize the driving force of neutralization between said acid and said base, thereby drawing additional acid from said first chamber as it forms and thereby maintaining the pH in said first chamber at a level conducive to continuous fermentation.
• Suitable membranes are permeable to amino or carboxylic acid, but block co-transport of impurities, so that a pure and concentrated solution of the corresponding soluble salt is formed in the product chamber, consuming no extra energy or reagents.
• membranes which block the cations, including the proton provide transport of the anions of the acid to the product chamber, balanced by counter-transport of hydroxyls or carbonate anions to the fermentation liquor.
• a simulated fermentation feed solution containing amino acid anions was prepared and a salt of said amino acid was recovered.
• a two-compartment cell was used.
• a Neosepta ACH-45 anion exchange membrane was introduced between the compartments. The membrane's active area was 5 cm 2 .
• the feed compartment contained a 1 M solution of monosodium glutamate with added glucose and dyes to simulated fermentation liquor.
• the product compartment contained 1 M solution of NaOH.
• the cell was mechanically shaken. Glutamate flux into the product compartment was about 1 10 ⁇ 5 mol/m 2 sec while Na ⁇ flux to the feed compartment was at least 2 orders of magnitude smaller. Glucose and dye transport into the product compartment was below detection limits.
• the monosodium glutamate solution obtained in the product compartment was concentrated to precipitate the monosodium glutamate therefrom.
• a simulated fermentation feed solution containing carboxylic acid was prepared and a salt of said carboxylic acid was recovered.
• a two- compartment cell was used.
• a Neosepta ACH-45 anion exchange membrane was introduced between the compartments. The membrane's active area was 5 cm 2 .
• the feed compartment contained a 0.5 M solution of monosodium citrate with added glucose and dyes to simulated fermentation liquor.
• the product compartment contained 1 M solution of NaOH.
• Citrate flux into the product compartment was about 3 10 ⁇ s mpl/m 2 sec while Na " * " flux to the feed compartment was at least 2 orders of magnitude smaller.
• Glucose and dye transport into the product compartment was below detection limits.
• the trisodium citrate solution obtained in the product compartment was concentrated to precipitate the trisodium citrate therefrom.

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• 1994
  • 1994-07-12 DE DE69420278T patent/DE69420278D1/de not_active Expired - Lifetime
  • 1994-07-12 AU AU74716/94A patent/AU7471694A/en not_active Abandoned
  • 1994-07-12 WO PCT/US1994/007585 patent/WO1995002716A1/en active IP Right Grant
  • 1994-07-12 EP EP94924454A patent/EP0725847B1/en not_active Expired - Lifetime
  • 1994-07-12 AT AT94924454T patent/ATE183661T1/de not_active IP Right Cessation
• 1996
  • 1996-01-11 NO NO19960131A patent/NO312275B1/no unknown
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